redesign default subs UX to use directories similar to digg and reddit

[plebe1us]

this design change brings a ton of positives and no negatives afaik. similar to 5chan's redesign of default boards.

• all default subs will be "directories", i.e. simple names as addresses that may resolve different boards over time.
• each directory will have its own pubsub voting page, this is key. for example, the directory "seedit.app/s/funny" will resolve the highest-voted self-described funny board (its address doesn't have to have "funny" in it, users will go to s/funny)
• every sub that applies to the s/funny voting page will appear in it, which raises its discoverability, and the more popular it gets the more votes it will get by token holders.
• if the highest voted sub for s/funny (ie, the sub that s/funny resolves to) degrades in quality, it will be downvoted by token holders, and the sub ranked second will take its place, resolving s/funny.
• it's much easier for users to subscribe to easy-to-understand, generic, common subs (the official directories), in fact they should be automatically subscribed to them just like reddit users are auto-subbed to those.
• we might end up having thousands of directories, with thousands of pubsub voting pages.
• as always, a seedit user can always connect directly to a community that does not resolve a directory, and subscribe to it, and it will appear in the homepage.